[Pacemaker] Initial quorum

[Devin Reade]

--On Wednesday, July 20, 2011 09:19:33 AM +0000 pskrap <pskrap at hotmail.com>
wrote:

> I have a cluster where some of the resources cannot run on the same node.
> All  resources must be running to provide a functioning service. This
> means that a  certain amount of nodes needs to be up before it makes
> sense for the cluster to start any resources.

Without knowing anything about your application, I would tend to question
this statement.  Is it true that you must not start *any* resources before
you have enough nodes, or is sufficient to say that the application
is not considered up until all resources are started?  It may not 
make sense to run any, but does it do any harm?

If you *can* start at least some resources before all nodes are available,
then I would expect that you could get by with defining colocation
constraints to ensure that some resources don't run on the same nodes,
perhaps augmenting things with some order constraints if necessary.

If your applications die or do other horrible stuff when only some subset
are running then I'd have a talk with your application developers
as it sounds like a larger robustness problem.

Devin